• gerard van weyenbergh

An art appraisal is not an art authentication.

Updated: Jul 9

An Art Authentication is not an Art Appraisal ...

It's a common mistake in the US that people are thinking that an art appraisal is equal to an art authentication. It could not be more wrong. An art appraisal is an opinion of the value of an item in fair market value or the replacement value. It doesn't engage the responsibility of the art appraiser if the painting is a fake or a copy.

A/ Fair market value: The amount for which personal property sells in a voluntary transaction between a buyer and a seller. The auction value is, most of the time, considered as fair market value.

B/ Replacement value: Replacement value or cost is the price that an entity would pay to replace an existing asset at the current market price with a similar asset. Usually, a gallery sells the replacement asset, that's why a replacement value is often compared with a gallery value. This gallery value is substantial as the value in an auction; it may as well be double or triple the value of the auction.

An art authentication process includes:

-Justification of authenticity by comparison with other works by the artist - Reestablish the works in the "catalogue raisonne"

- Comparison with other works made by the same artist of the same period

- Comparison with other artists of the same period or movement.

- Reestablish history of the painting

- Research of the history, provenance of the painting

- Graphology analysis of handwriting

- Signature analysis

- On-site analysis of the painting

- Eventually study of the pigments

- Study of the support

- Study of the manner

- Wood lamp test

- The Conclusion

- Presentation of the file to the solely recognized expert for the artist.


Each major artist has his own "SOLELY RECOGNIZED AUTHENTICATOR." Sotheby's, Christie's, whatever major gallery doesn't have the authority to give an authentication certificate for an item. Sotheby's and Christie's or any respectable auction house will consult the solely recognized authenticator for an artist before to admit it in their auction. They should do so, but we know today that many fakes are sold in these major auction houses. Art experts, in general, may give an opinion at their responsibility ( don't forget that in the USA everybody can sue everybody for whatever reason).

If the solely recognized authenticator refuses to authenticate the artwork, experts who emit an opinion on the artwork may face a lawsuit.

In the USA, because of the possibility to sue an individual or an organization, several major institutions, so the Warhol, Pollock, Haring, De Kooning, foundation decided to stop the authentication service. For these painters, if you do not have an authentication before they decided to close the authentication service, there is one solution left: making a file that proves the authenticity of the item with indisputable and verifiable valid arguments.